Precision spectroscopy in the charmonium mass region using antiproton annihilation PANDA at FAIR

J. Ritman (FZ-Jülich/RUB)

Precision spectroscopy in the charmonium mass region using

antiproton annihilation

PANDA at FAIR


Goal

• In the next 1-2 years PANDA should prepare a physics book that details specific observables and background, provides detailed simulations of the sensitivity to the physics parameters


Main Physics Issues at PANDA

• Confinement– Charmonium (see talk of Diego Bettoni)– Existence of exotic hadrons ()

• Properties of hadrons– Hadronic mass, charm in matter (A. Gillitzer)– EM coupling, DY, hard processes etc. (Michael Düren)– Spectroscopy of charmed baryons ()– New D-Meson states– New baryon states “at the end of the alphabet”

• Strange Baryons in strong fields (J. Pochodzalla)


Precision Spectroscopy

• High statistical precision

• High mass resolution– Crystal Ball: typical

resolution ~ 10 MeV– Fermilab: 240 keV

p/p < 10-4 needed


G. Bali et al., hep-lat/0003012

Confinement on the Lattice

aV(r) br

r= - +

q q

Distance between Quarks [fm]


Quark-Antiquark Binding Charmonium Physics

DD

DD*

ψ(11D2)

ψ(13D2)

ψ(13D3)

ψ(13D1)

Mcc

[G

eV

/c2]

ηc(11S0)

ηc(21S0)

J/ψ(13S1)

χc0(13P0)

χc1(13P1)

χc2(13P2)

h1c(11P1)

2.9

3.0

3.1

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

4.0D*D*

ψ(33S1)

pp [G

eV

/c]

ψ(23S1)

χc0(23P0)

χc1(23P1)

χc2(23P2)

h1c(21P1)ηc(31S0)

3.4

4.1

4.8

5.5

6.3

7.1

8.0

JP=0+ 1- 1+ (0,1,2)+ 2- (1,2,3)-

… Exclusive ChannelsHelicity violationG-Parity violationHigher Fock state contributions

Open questions …

ηc – inconsistencies

ηc’ - ψ(2S) splitting

h1c – unconfirmed

Peculiar ψ(4040)

Terra incognita for 2P and 1D-States

Spin dependence of potentialLQCD NRQCD


“Exotic” Hadrons

• Quarkmodels usually account for qq states

• Other color neutral configurations with same quantum numbers can (and will mix)

• Decoupling only possible for

– narrow states– vanishing leading

qq term

qq

(q )(q )q q

+

(q )gq

+

gg

+

= (q ) gi i j jq

+........


Hadronic Molecules: Example f0

• Breit-Wigner will be distorted near thresholds. (Haidenbauer,Hanhart, Kalishnikova,...)

• Flatte


Charmed Hybrids

• LQCD: –gluonic excitations of the

quark-antiquark-potential may lead to bound states

– -potentialfor one-gluon exchange

– -potential from excited gluon flux

–mHcc ~ 4.2-4.5 GeV/c2

• Light charmed hybrids

could be narrow if open

charm decays are

inaccessible or suppressed

3

3.5

4

1 2

R/r0

V(R)/GeV

J/ψ

χc

ψ‘

Hcc

DD

RBRB


Charm Hybrids

distance between quarksGround state has spin exotic quantum numbers


Glueballs

gg

g

RG

GR

BGGRRB

C. Morningstar PRD60, 034509 (1999)Self interaction between gluons

Construction of color-neutral hadrons with gluons possible

exotic glueballs don‘t mix with mesons (qq)

0--, 0+-, 1-+, 2+-, 3-+,...


Recently Discovered Hadrons


126753 Events in peak

27333 Events in peak

M = 2316.8 0.4 MeV/c2 = 8.6 0.5 MeV/c2

Resolution from MC is

= 8.9 0.2 MeV/c2

M = 2317.6 1.3 MeV/c2 = 8.8 1.1 MeV/c2

DsJ*(2317)+ Ds+π0

Ds+ K+K–π+π0

DsJ*(2317)+ Ds+π0

Ds+ K+K–π+

Com

bin

ato

rial D

S*+

DS

*+(2

11

2)

BABAR

BABAR

New State in Two Ds+ Modes

Babar, Aubert et al., PRL 90(2003)242001


ΔM = 344.6 ± 1.2 MeV/c2

M = 2456.5 ± 1.4 MeV/c2

Ds* Sideband

m(K+K-π+π0γ)- m(K+K-π+γ)[GeV/c2] [GeV/c2]

BABARBABAR

DifferenceSignal + Sideband

Search for a Ds+π0γ State

N = 140 ± 22

m(K+K-π+π0γ)- m(K+K-π+γ)

Babar, Preliminary, PRD, Journal Draft


Recent Open Charm Discoveries

• The DS± Spectrum

• |cs> + c.c.

• was not expected to reveal any surprises

Potential model

Old measurements

New observations

• Are these molecules?

0 1 0 1 2 3

Ds

Ds*

DsJ*

(2317)

Ds1

m [G

eV/c

2 ]D0K

D*K

DsJ

(2458)

Ds2*

JP


Hadrons in Nuclear Matter

• Hadronic mass arises from interaction with the vacuum, expect changes to the spectral function in nuclear matter.

M. Lutz, C.Korpa, PLB 633 (2006) 43


• P-Linac• SIS18• SIS100 (30 GeV)• PBar production Target• RESR/CR• HESR

The HESR in the FAIR Topology


Basic Data

• Circumference 574 m (space included for PAX extension)

• Momentum:1.5 to 15 GeV/c• HESR as synchrotron• Injection of (anti-)protons from

RESR at 3.8 GeV/c• Acceleration rate 0.1 GeV/c/s• Electron cooling up to 8.9 GeV/c• Stochastic cooling above

3.8 GeV/c


Electron Cooling : HR-Mode @ p = 8.9 GeV/c

cooling OFF

red: horizontalblue: vertical

• Electron cooling and target ON

• Equilibrium dominated by IBS

Final rms-momentum spread with target and IBS :

3.0 x 10-5

At 3.8 GeV/c 4x10-5


Stochastic Cooling: HL-Mode @ p = 3.8 GeV/c

Transverse and longitudinal

stochastic coolingred: horizontalblue: vertical rms-emittances

rms relative momentum spread

Including IBS+Target

Final rms-momentum spread: 1.5 x 10-4


Example: Stochastic Cooling at 4.8 GeV/cHR- Mode

2

4

6

8

10

12

14

0 50 100 150 200

Stochastic Momentum Cooling at T = 4 GeV

rms

×

105

t [s]

High Resolution Mode with cut

= 10-3

105 dB, 3 W

110 dB, 10 W

115 dB, 31 W

H. S

tock

hors

t, 2

1/09

/20

05, M

om

entu

m C

ool

ing

at 4

GeV

no

tran

s

• Final rms-momentum spreadin the High Resolution Modeabove 3 GeV:

4 x 10-5

in about 100 s.

• Only longitudinal cooling:

Initial emittance will increasefrom 0.08 mm mrad to 8 mm mrad within one hour due to target-beam interaction.


Measuring Area


The PANDA Detector

12 m

5 m


WASA Pellet Target at COSY

• Photo from test stand, now in the COSY ring

• Operational, optimizationproceeding

• Beam on target in Sept.


Summary

• Strong QCD: many interesting open questions related to– Confinement– Hadron (spin) structure

• High rates with antiproton beams– Charm quark mass range PANDA/HESR


Outline

• Strong QCD

• Confinement– Potential– Types of hadrons

• (Broken) Symmetries in Hadronic Systems (SB)

• Planned experiments with PANDA at FAIR


Strong QCD

• EM=1/137 increases by ~ 2.7% between E=0 and MZ

• S rises dramatically to ~ 1 for distances of about 1 fm

Strong QCD- Perturbation theory fails

- New Phenomena appear- Confinement- Hadronic mass generation


Charmonium – the Positronium of QCD

3D2

2900

3100

3300

3500

3700

3900

4100

c(3590)

c(2980)

hc(3525)

(3097)

(3686)

(3770)

(4040)

0(3415)

1(3510) 2(3556)

3D1

3D3

1D2

3P2(~ 3940)

3P1(~ 3880)

3P0(~ 3800)

(~ 3800)

1 fm

C C

~ 600 meV -1000

-3000

-5000

-700011S

0

13S1

21S0 23S

121P

1 23P2

23P1

23P0

031S

0 31D

2 33D2

33D1

33D2

Ionisations energy33S

1

e+ e-0.1 nm

Binding energy [meV]

Mass [MeV]

DDThreshold

8·10-4 eV

10-4 eV

• Positronium • Charmonium


The Spin-Dependent Potential

SD LS SS TH V V V

2

( )3

2SV

LSc

dVdVL SV

m r dr dr

1 2 2

2

2( )

3SS Vc

S SV V r

m

2

2

2 2

ˆ ˆ2 3 112

V VT

c

S r S r S dV d VV

m r dr dr

spin-orbit(fine structure)

spin-spin(hyperfine structure)

tensor

VS and VV are the scalar and vector components of the non-relativistic potential


Why Antiprotons?

• e+e- annihilation via virtual photon: to 1st order only states with Jpc = 1--

• In pp annihilation all mesons can be formed

• Resolution of the mass and width is only limited by the beam momentum resolution

Measured rate

Beam

Resonance cross

section

CM Energy


Central Tracking Detectors

• Straw-Tubes (or TPC…)

• MVD


Micro Vertex Detectors

Needed for D meson identification (c ~ 100,300 m)

FZJ (IKP+ZEL+ZAT) is taking on the following activities:• System design• Simulations• Readout chain • Prototype testing• Services

Together with Dresden


Central Tracker

Straw-Tubes alternative: TPC with GEM readout

Building on in-house expertise (TOF, WASA)IKP is taking on:

• Design - low mass (full system ~1%X0), self supporting - longitudinal coordinate: skewed double-layers, or time dependent charge division• Simulation• Prototyping


Prototype Development

Single Tube, Fe Sourcez-Resolution ~ 8 mm

Two tubes, Sr Sourcez-Resolution ~ 35 mm

Precision spectroscopy in the charmonium mass region using antiproton annihilation PANDA at FAIR

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